package isogram

// BenchmarkIsIsogram-4      200000        7931 ns/op
// PASS
// ok    _/Users/Gantian/exercism/go/isogram 1.678s

import (
	"strings"
	"unicode"
)

const testVersion = 1

func IsIsogram(input string) (r bool) {
	input = strings.ToLower(input)

	for _, v := range input {
		if unicode.IsLetter(v) && strings.Count(input, string(v)) > 1 {
			return
		}
	}

	r = true
	return
}
